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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>,
        Jim Mattson <jmattson@google.com>, erdemaktas@google.com,
        Connor Kuehl <ckuehl@redhat.com>,
        Sean Christopherson <seanjc@google.com>
Subject: [RFC PATCH v5 071/104] KVM: TDX: restore debug store when TD exit
Date:   Fri,  4 Mar 2022 11:49:27 -0800
Message-Id: <c7f81bd80af0f57ff2fabef24a218fb43c3d0e3c.1646422845.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Because debug store is clobbered, restore it on TD exit.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/events/intel/ds.c | 1 +
 arch/x86/kvm/vmx/tdx.c     | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 376cc3d66094..cdba4227ad3b 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2256,3 +2256,4 @@ void perf_restore_debug_store(void)
 
 	wrmsrl(MSR_IA32_DS_AREA, (unsigned long)ds);
 }
+EXPORT_SYMBOL_GPL(perf_restore_debug_store);
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 3cb2fbd1c12c..37cf7d43435d 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -620,6 +620,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu)
 	tdx_vcpu_enter_exit(vcpu, tdx);
 
 	tdx_user_return_update_cache();
+	perf_restore_debug_store();
 	tdx_restore_host_xsave_state(vcpu);
 	tdx->host_state_need_restore = true;
 
-- 
2.25.1